The conventional method for making copper wire involves the following steps. Electrolytic copper (whether electrorefined, electrowon, or both) is melted, cast into bar shape, and hot rolled into a rod shape. The rod is then cold-worked as it is passed through drawing dies that systematically reduce the diameter while elongating the wire. In a typical operation, a rod manufacturer casts the molten electrolytic copper into a bar having a cross section that is substantially trapazoidal in shape with rounded edges and a cross sectional area of about 7 square inches; this bar is passed through a preparation stage to trim the corners, and then through 12 rolling stands from which it exits in the form of a 0.3125" diameter copper rod. The copper rod is then reduced to a desired wire size through standard round drawing dies. Typically, these reductions occur in a series of machines with a final annealing step and in some instances intermediate annealing steps to soften the worked wire.
The conventional method of copper wire production consumes significant amounts of energy and requires extensive labor and capital costs. The melting, casting and hot rolling operations subject the product to oxidation and potential contamination from foreign materials such as refractory and roll materials which can subsequently cause problems to wire drawers generally in the form of wire breaks during drawing.
By virtue of the inventive process, copper wire is produced in a simplified and less costly manner when compared to the prior art. The inventive process utilizes a copper source such as copper shot, copper oxide or recycled copper. This process does not require use of the prior art steps of first making copper cathodes then melting, casting and hot rolling the cathodes to provide a copper rod feedstock.